Hard anodization is an electro-chemical process that hardens aluminum. During hard-anodization, aluminum is submerged in an acid bath, and then subjected to electrical charges. The result is a chemical reaction wherein the surface of the aluminum combines with oxygen to become aluminum oxide. Hard anodizing is more commonly found in industrial or commercial applications than in consumer products.
Hard Chrome plating is an electrolytic process, which utilizes a chromic acid-based electrolyte. Hard chrome plating is a process that is extensively used by aircraft manufacturers and military aircraft maintenance depots to provide wear and/or corrosion resistance to components or to restore dimensional tolerance to components.